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From: Uladzislau Rezki <urezki@gmail.com>
Date: Thu, 8 Feb 2024 19:27:39 +0100
To: Andrew Morton <akpm@linux-foundation.org>,
	Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	Kieran Bingham <kbingham@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	casper.li@mediatek.com, chinwen.chang@mediatek.com,
	qun-wei.lin@mediatek.com, linux-mm@kvack.org, urezki@gmail.com,
	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org
Subject: Re: [PATCH] scripts/gdb/vmalloc: fix vmallocinfo error
Message-ID: <ZcUdG5snmTW1ldx3@pc636>
References: <20240207085856.11190-1-Kuan-Ying.Lee@mediatek.com>
 <20240207155623.a943328ba0b77859246e0d9f@linux-foundation.org>
 <20240207155929.cc107bcc14b982789bdc9fab@linux-foundation.org>
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In-Reply-To: <20240207155929.cc107bcc14b982789bdc9fab@linux-foundation.org>

On Wed, Feb 07, 2024 at 03:59:29PM -0800, Andrew Morton wrote:
> On Wed, 7 Feb 2024 15:56:23 -0800 Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > > [1] https://lore.kernel.org/linux-mm/20240102184633.748113-1-urezki@gmail.com/
> > 
> > vmap_area_list was removed by https://lkml.kernel.org/r/20240102184633.748113-6-urezki@gmail.com
> > 
> > So I think this patch is actually a fix against mm.git:mm-unstable's
> > mm-vmalloc-remove-vmap_area_list.patch?
> > 
> > However this gdb function was probably probably broken earlier in that
> > series, so perhaps this patch would be best staged as a predecessor to
> > Ulad's vmalloc series.
> 
> ie, this:
> 
> 
> From: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
> Subject: scripts/gdb/vmalloc: fix vmallocinfo error
> Date: Wed, 7 Feb 2024 16:58:51 +0800
> 
> The patch series "Mitigate a vmap lock contention" removes vmap_area_list,
> which will break the gdb vmallocinfo command:
> 
> (gdb) lx-vmallocinfo
> Python Exception <class 'gdb.error'>: No symbol "vmap_area_list" in current context.
> Error occurred in Python: No symbol "vmap_area_list" in current context.
> 
> So we can instead use vmap_nodes to iterate all vmallocinfo.
> 
> Link: https://lkml.kernel.org/r/20240207085856.11190-1-Kuan-Ying.Lee@mediatek.com
> Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
> Cc: Casper Li <casper.li@mediatek.com>
> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Cc: Chinwen Chang <chinwen.chang@mediatek.com>
> Cc: Jan Kiszka <jan.kiszka@siemens.com>
> Cc: Kieran Bingham <kbingham@kernel.org>
> Cc: Matthias Brugger <matthias.bgg@gmail.com>
> Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  scripts/gdb/linux/vmalloc.py |   56 +++++++++++++++++----------------
>  1 file changed, 29 insertions(+), 27 deletions(-)
> 
> --- a/scripts/gdb/linux/vmalloc.py~scripts-gdb-vmalloc-fix-vmallocinfo-error
> +++ a/scripts/gdb/linux/vmalloc.py
> @@ -29,32 +29,34 @@ class LxVmallocInfo(gdb.Command):
>          if not constants.LX_CONFIG_MMU:
>              raise gdb.GdbError("Requires MMU support")
>  
> -        vmap_area_list = gdb.parse_and_eval('vmap_area_list')
> -        for vmap_area in lists.list_for_each_entry(vmap_area_list, vmap_area_ptr_type, "list"):
> -            if not vmap_area['vm']:
> -                gdb.write("0x%x-0x%x %10d vm_map_ram\n" % (vmap_area['va_start'], vmap_area['va_end'],
> -                    vmap_area['va_end'] - vmap_area['va_start']))
> -                continue
> -            v = vmap_area['vm']
> -            gdb.write("0x%x-0x%x %10d" % (v['addr'], v['addr'] + v['size'], v['size']))
> -            if v['caller']:
> -                gdb.write(" %s" % str(v['caller']).split(' ')[-1])
> -            if v['nr_pages']:
> -                gdb.write(" pages=%d" % v['nr_pages'])
> -            if v['phys_addr']:
> -                gdb.write(" phys=0x%x" % v['phys_addr'])
> -            if v['flags'] & constants.LX_VM_IOREMAP:
> -                gdb.write(" ioremap")
> -            if v['flags'] & constants.LX_VM_ALLOC:
> -                gdb.write(" vmalloc")
> -            if v['flags'] & constants.LX_VM_MAP:
> -                gdb.write(" vmap")
> -            if v['flags'] & constants.LX_VM_USERMAP:
> -                gdb.write(" user")
> -            if v['flags'] & constants.LX_VM_DMA_COHERENT:
> -                gdb.write(" dma-coherent")
> -            if is_vmalloc_addr(v['pages']):
> -                gdb.write(" vpages")
> -            gdb.write("\n")
> +        nr_vmap_nodes = gdb.parse_and_eval('nr_vmap_nodes')
> +        for i in range(0, nr_vmap_nodes):
> +            vn = gdb.parse_and_eval('&vmap_nodes[%d]' % i)
> +            for vmap_area in lists.list_for_each_entry(vn['busy']['head'], vmap_area_ptr_type, "list"):
> +                if not vmap_area['vm']:
> +                    gdb.write("0x%x-0x%x %10d vm_map_ram\n" % (vmap_area['va_start'], vmap_area['va_end'],
> +                        vmap_area['va_end'] - vmap_area['va_start']))
> +                    continue
> +                v = vmap_area['vm']
> +                gdb.write("0x%x-0x%x %10d" % (v['addr'], v['addr'] + v['size'], v['size']))
> +                if v['caller']:
> +                    gdb.write(" %s" % str(v['caller']).split(' ')[-1])
> +                if v['nr_pages']:
> +                    gdb.write(" pages=%d" % v['nr_pages'])
> +                if v['phys_addr']:
> +                    gdb.write(" phys=0x%x" % v['phys_addr'])
> +                if v['flags'] & constants.LX_VM_IOREMAP:
> +                    gdb.write(" ioremap")
> +                if v['flags'] & constants.LX_VM_ALLOC:
> +                    gdb.write(" vmalloc")
> +                if v['flags'] & constants.LX_VM_MAP:
> +                    gdb.write(" vmap")
> +                if v['flags'] & constants.LX_VM_USERMAP:
> +                    gdb.write(" user")
> +                if v['flags'] & constants.LX_VM_DMA_COHERENT:
> +                    gdb.write(" dma-coherent")
> +                if is_vmalloc_addr(v['pages']):
> +                    gdb.write(" vpages")
> +                gdb.write("\n")
>  
>  LxVmallocInfo()
> _
> 
Thanks for fixing and helping!

--
Uladzislau Rezki